Spare tire undercover

ABSTRACT

An aerodynamic spare tire cover system is provided for use with a spare tire stored on a vehicle underbody. The cover system can be used to cover a full sized spare tire or a temporary spare tire, while providing the same aerodynamic qualities. The cover system includes an annular spare tire cover defining a central aperture, a removable center cap for selectively covering the central aperture, a center spacer supported by the annular spare tire cover that is adjustable between a first position and a second position depending on whether a full sized spare or temporary spare is being covered, and removable spacers supported by the annular spare tire cover. A full sized spare tire and the center spacer in the first position space the spare tire cover the same distance from a position on the vehicle underbody, on the opposite side of the spare tire, as a temporary spare tire, and the center spacer in the second position.

BACKGROUND OF THE INVENTION

Maximizing fuel efficiency in modern vehicle design is a prime concernof engineers. One area that contributes to fuel efficiency of a vehicleis vehicle aerodynamics. The pattern of air movement over a vehicle hasbeen closely scrutinized over time and is well understood. Morerecently, the flow of air beneath a vehicle has also been closelyscrutinized. In one aspect of vehicle underbody design, when moresurfaces can be made consistently smooth, underbody aerodynamics isimproved.

For years, tractor trailer vehicles and heavy duty pick-up trucks havestored spare tires (including a wheel rim) on the vehicle underbody.This type of spare tire storage is becoming more prevalent on passengervehicles as well because more interior space can be reserved for storageof personal items or cargo.

There is a continuing debate over the desirability of using, inpassenger vehicles, a full sized spare tire as compared to a smallertemporary spare tire. On one hand, the full sized spare tire can beswitched with a damaged tire and used indefinitely while providing thesame performance characteristics as the remaining three tires. On theother hand, use of a temporary spare, when in storage, takes up a smallamount of storage room and is light, thus, increasing the vehicle'soverall fuel efficiency. Each spare tire type lacks the advantages ofthe other type.

When a spare tire is secured to a vehicle underbody, either type ofspare tire can be held by a known hoist or clamping system. However,what is desired is a way of providing a consistent smooth air flowsurface on the underside of the vehicle, no matter which type of sparetire is used so superior vehicle aerodynamics can be maintained.

SUMMARY OF THE INVENTION

The present invention provides an improvement over the prior art byproviding a system that may be used with either a full sized spare tireor temporary spare tire and in each instance provide a smooth,consistent, aerodynamic surface beneath the spare tire when it is heldbeneath a vehicle.

In accordance with the present invention, an aerodynamic spare tirecover system for use with a spare tire stored on a vehicle underbodyincludes an annular spare tire cover defining a central aperture. Thecover system also includes a removable center cap for selectivelycovering the central aperture and an adjustable center spacer supportedby the annular spare tire cover. The cover system further includesremovable peripheral spacers supported by the annular spare tire cover.When using the cover system of the present invention, a full sized sparetire spaces the annular spare tire cover generally the same distancefrom a base of a spare tire storage well as a combination of a temporaryspare tire and center spacer. The peripheral spacers provide additionalstability and consistent spacing between the annular cover and thetemporary spare. As a result, no matter which type of spare tire isstored, the annular spare tire cover and center cap remain generallyflush with the surrounding underbody of the vehicle at the crest of thespare tire well.

These and other aspects of the invention are herein described inparticularized detail with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of the spare tire cover system;

FIG. 2 is an exploded view of the spare tire cover system;

FIG. 3 is a perspective view of the spare tire cover system with thecenter cap removed;

FIG. 4 is a side elevational view of a vehicle including a full sizedspare tire and the spare tire cover system;

FIG. 5 is a close-up side elevational view of a vehicle including atemporary spare tire and the spare tire cover system;

FIG. 6 is a close-up side elevational view of a vehicle including a fullsized spare tire and the spare tire cover system; and

FIG. 7 is a side elevational view of a vehicle including a full sizedspare tire that is partially removed.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, a spare tire cover system 10 according to thepresent invention is illustrated. The spare tire cover system 10includes an annular spare tire cover 12, a center cap 14, an adjustablecenter spacer 16 and peripheral spacers 18. The term spare tire is usedthroughout and refers to a known wheel and tire combination.

Referring to FIGS. 1-3, the spare tire cover system 10 is showncompletely detached from a spare tire. The annular spare tire cover 12defines a first generally flat surface 20 and an opposite, secondgenerally flat surface 22. A peripheral edge 21 of the annular sparetire cover 12 is curled in the direction of the second generally flatsurface 22. The annular spare tire cover 12 also defines a centralaperture 23. A seat 24 is disposed around the central aperture 23 and iscountersunk with respect to the first generally flat surface 20. Fourslots 26 are defined by the seat 24.

The second generally flat surface 22 defines four circular support areas28 configured along a circle having a radius “A”. Two slots 30 areprovided along a circumference of each circular support area 28. Abi-level circular wall 32 protrudes from the second flat surface 22directly adjacent to the central aperture 23. The wall 32 includes astepped top edge 34 alternating between first and second heights. Flatsteps 36 and 38 extend from the top edge 34 of the wall toward thecenter of the annular spare tire cover 12. Preferably, there are fourupper steps 36 at the first height of the stepped top edge 34 and fourlower steps 38 at the second height of the stepped top edge 34. Withineach step 36 and 38, a top surface defines a small aperture 40. Risers39 extend vertically from both ends of each lower step 38 upward to anadjacent upper step 36. No wall is provided beneath each step 36 and 38on a side opposite the wall 32. The area under each upper step 36 andeach lower step 38 is hollow.

The center cap 14 is provided with an outer flange 50 and a steppedinner surface 52. The outer flange 50 is annular and defines four tabs54. The inner surface 52 is divided into quadrants 56 by channels 58each having a bottom that is level with the outer flange 50. Eachquadrant 56 of the inner surface 52 defines a circular support area 57,including slots 59, that is sized the same as the support areas 28 onthe annular cover 12. Each tab 54 includes a vertical wall 53 and ahorizontal wall 55 that extends in a cantilever manner from a top of thevertical wall 53. A void is provided in the outer flange 50 below eachhorizontal wall 53.

The adjustable center spacer 16 is shaped like a truncated cone andincludes a side surface 63 and a top surface 62. A base end 61 of theside surface 63 is located opposite an end that meets the top surface62. Four wing portions 60 of the center spacer 16 extend radiallyoutward from the side surface 63 at the base end 61. Each wing portion60 includes a lockable clip 66 that points toward the top surface 62 ofthe center spacer 16. The top surface 62 is flat and defines a centralaperture 64.

The peripheral spacers 18 preferably are four posts that are selectivelyattachable to the secondary surface 22 of the annular cover 12 each at asupport area 28. Each spacer 18 includes two tabs 72 at its bottom. Theheight of each spacer 18 is preferably equal to the difference betweenthe first and second heights of the bi-level wall 34.

The spare tire cover 12, center cap 14, adjustable center spacer 16 andperipheral spacers 18 are all preferably made from fiberglass filledpolypropylene, but may be made from other materials as well, such asnylon, other homogeneous polymers or reinforced polymers.

Referring to FIGS. 5-6, assembly of the spare tire cover system 10 isshown. The center spacer 16 is attachable to the annular cover 12 in twodistinct, alternate configurations. In a first configuration shown inFIG. 5, the top surface 62 of the center spacer 16 is placed through thecentral aperture 23 of the annular cover 12 and advanced until the wingportions 60 of the center spacer 16 fit adjacent the bi-level circularwall 32 and against the upper steps 36 that extend from the wall 32. Asa result, the top surface 62 rises to a first height above the flatsurface 22 of the annular cover 12. The lockable clips 66 on the wingportions 60 engage the small apertures 40 in the upper steps 36 by meansof a snap fit.

Referring to FIG. 6, the center spacer 16 is changed to a secondconfiguration after pressing down on the top surface 62 to unsnap thelockable clips 66 from the apertures 40 in the upper steps 36. Thecenter spacer 16 is rotated until the wing portions 60 align with thelower steps 38 and the spacer 16 is again moved upward until thelockable clips 66 engage the holes 40 in the lower steps 38 by means ofa snap fit. The top surface 62 is at a second, lower, height above theflat surface 22 as compared to the first configuration.

The center cap 14 is then secured to the annular cover 12. The centercap 14 is placed over the central aperture 23, the outer flange 50fitting against the seat 24. The center cap 14 is rotated until the tabs54 on the center cap 14 engage the slots 26 in the seat 24 of theannular cover 12. To remove the center cap 14, the center cap 14 issimply rotated in an opposite direction.

The peripheral spacers 18 are configurable in two positions, the firstbeing a functional position and the second a storage position. Referringto FIG. 5, the peripheral spacers 18 are placed on the support areas 28of the annular cover 12, representing a functional position. The tabs 72on the individual spacers 18 engage the slots 30 in the annular coversupport areas 28. Referring to FIG. 6, the peripheral spacers 18 areremoved from the support areas 28 in the annular cover 12 and placed onthe support areas 57 of the center cap 14, representing a storageposition. The tabs 72 on the individual spacers 18 engage the slots 59of the support area 57. When in the storage position, the spacers 18 donot contact the spare tire when the cover system is in use.

Referring to FIGS. 4-6, the cover system 10 is used to provide anaerodynamically smooth surface that covers the spare tire 100 on theunderside of a vehicle 102. The spare tire 100 is typically held underthe vehicle using a hoist 104. The hoist 104 is of a type well known inthe art and includes a cord or chain 106, a retractor 108 and a stop110. The retractor 108 is attached to the body of the vehicle 102. Thecord 106 extends from the retractor 108 and passes through a hole withinthe center of the spare tire 100 and through the central aperture 64 inthe center spacer 16. The stop 110 abuts the center spacer 16 on a sideopposite the top surface 62 and pulls the top surface 62 against thespare tire 100, thus, holding both the spare tire 100 and cover system10 in place. By putting the center cap 14 in place, the stop 110 ishidden from view.

Through the use of the center spacer 16 and peripheral spacers 18, thedistance between a base of a spare tire well 110 of the vehicle 102 andthe annular cover 12 is generally consistent no matter whether a fullsized spare tire 100 or temporary spare tire 101 is stored. As a result,the annular cover 12 and center cap 14 are consistently generally flushwith a lower surface 112 of the underbody of the vehicle 102 at thecrest of the spare tire well.

Referring to FIG. 7, to remove the spare tire 100 for use, the hoist 104is actuated to lower the spare tire 100 and cover system 10. The centercap 14 is also removed from the cover system 10, either before oractuating the hoist 104. After the spare tire 100 has been lowered,there is sufficient slack in the cord 106 of the hoist to allow the stop110 to be detached from the cord 106 or fit through the aperture 64 onthe center spacer 16 and the hole in the spare tire 100. The annularcover 12 and center spacer 16 are put aside and the spare tire 100 isthen ready to be used.

Other types of fasteners known in the art may be used to hold theadjustable spacer to the annular cover and the center cap to the annularcover.

The cover system is a simple device that provides a consistentaerodynamic surface on the underside of a vehicle no matter what type ofspare tire is stored there. The combination of the annular cover andcenter cap create a generally flat surface that is generally flush witha lower surface of the vehicle underbody, thus providing superiorunderbody aerodynamics. The spacing elements (center and peripheral) arestored with the cover system at all times and never have to be recoveredfor use from some other storage location. The shape of the center spacerallows for the center spacer to be easily fit into the annular cover.The cover system may be used on vehicle that does not include a well forstoring the spare tire because significant aerodynamic advantages arestill provided by having a flat surface covering at least the bottom ofthe spare tire. The cover system is preferably stored inside of thevehicle when no spare tire is stored on the underside of the vehicle,for example when the spare tire is being repaired.

Although the invention has been shown and described with reference tocertain preferred and alternate embodiments, the invention is notlimited to these specific embodiments. Minor variations andinsubstantial differences in the various combinations of materials andmethods of application may occur to those of ordinary skill in the artwhile remaining within the scope of the invention as claimed andequivalents.

1. An aerodynamic spare tire cover system for use on a spare tire andwheel combination stored on a vehicle underbody, the system comprising:an annular spare tire cover having a diameter sufficient to cover atleast a portion of both the tire and wheel in a spare tire and wheelcombination, and defining a central aperture; a removable center cap forselectively covering the central aperture of the annular spare tirecover; a center spacer selectively adjustable between a first positionand a different second position with respect to the spare tire cover,where in each position the center spacer is supported by the spare tirecover; and a plurality of removable peripheral spacers supported by theannular spare tire cover, wherein the center spacer, when supported inthe first position in the spare tire cover, cooperates with a full sizedspare tire to space the spare tire cover a first distance from a firstportion of the underbody of the vehicle, and wherein the center spacer,when supported in the second position in the spare tire cover,cooperates with a temporary spare tire to space the spare tire cover asecond distance, generally equivalent to the first distance, from thefirst portion of the underbody of the vehicle.
 2. The aerodynamic sparetire cover system of claim 1, wherein the removable center cap providesplanar storage surfaces, including slots that engage tabs on theperipheral spacers, for the peripheral spacers when the peripheralspacers are not used to space the spare tire cover from the spare tire.3. The aerodynamic spare tire cover system of claim 1, wherein theremovable center cap further comprises a plurality of tabs thatselectively interlock with a plurality of slots on the annular sparetire cover.
 4. The aerodynamic spare tire cover system of claim 1,wherein when the center spacer is in either the first position or thesecond position, the annular spare tire cover is generally flush with asecond portion of the vehicle underbody.
 5. The aerodynamic spare tirecover system of claim 1, wherein the first portion of the vehicleunderbody is the base of a spare tire well.
 6. The aerodynamic sparetire cover system of claim 1, wherein: the annular spare tire coverincludes: a bi-level circular wall; a plurality of first steps extendingfrom the circular wall toward a center of the spare tire cover at afirst height; and a plurality of second steps extending from thecircular wall toward a center of the spare tire cover at a secondheight; and the adjustable center spacer includes a plurality of wingportions that selectively fit either against the first steps when thecenter spacer is in the first position or against the second steps whenthe center spacer is in the second position.
 7. The aerodynamic sparetire cover system of claim 1, wherein the center spacer has a truncatedcone shape.
 8. The aerodynamic spare tire cover system of claim 6,wherein the wing portions extend outwardly from a base of the centerspacer.
 9. The aerodynamic space tire cover system of claim 1, whereinthe spacers are posts having a truncated cone shape.
 10. The aerodynamicspare tire cover system of claim 1, wherein the center cap is generallyflush with the spare tire cover when the center cap covers the centralaperture of the spare tire cover.
 11. The aerodynamic spare tire coversystem of claim 6, wherein the center spacer and center cap are separateelements.
 12. The aerodynamic spare tire cover system of claim 6,wherein the plurality of removable peripheral spacers are supported onthe annular spare tire cover in a position between the central apertureand an outer edge of the annular spare tire cover.
 13. The aerodynamicspare tire cover system of claim 6, wherein the spare tire cover isgenerally planar between the central aperture and a peripheral concaveedge portion.
 14. The aerodynamic spare tire cover system of claim 6,wherein the largest diameter of the center spacer is less than thediameter of the center cap and largest diameter of the spare tire cover.15. An aerodynamic spare tire cover system for use on a spare tirestored on a vehicle underbody, the system comprising: an annular sparetire cover defining a central aperture; a removable center cap forselectively covering the central aperture of the annular spare tirecover; a center spacer selectively adjustable between a first positionand a different second position with respect to the spare tire cover,where in each position the center spacer is supported by the spare tirecover; and a plurality of removable peripheral spacers supported by theannular spare tire cover, wherein the center spacer, when supported inthe first position in the spare tire cover, cooperates with a full sizedspare tire to space the spare tire cover a first distance from a firstportion of the underbody of the vehicle, and wherein the center spacer,when supported in the second position in the spare tire cover,cooperates with a temporary spare tire to space the spare tire cover asecond distance, generally equivalent to the first distance, from thefirst portion of the underbody of the vehicle wherein: the annular sparetire cover includes: a bi-level circular wall; a plurality of firststeps extending from the circular wall toward a center of the spare tirecover at a first height; and a plurality of second steps extending fromthe circular wall toward a center of the spare tire cover at a secondheight; and the adjustable center spacer includes a plurality of wingportions that selectively fit either against the first steps when thecenter spacer is in the first position or against the second steps whenthe center spacer is in the second position.